Dot matrix print heads with adjustable print needle guides are used for high-speed printing and/or calligraphy. In high-speed printing, the printing is accomplished with unchanged position of the print needle guide in successive lines from left to right or from right to left. In calligraphy (specifically, in relatively high-speed calligraphy), the printing is accomplished by going over the same line twice in printing passes going in the same or opposite directions and by adjustment of the print needle guide. In this connection, the needle column consists, e.g., of seven to nine needles and can thus be in one column. Of course it is possible, if the structurally available space in the dot matrix print head permits such a design, to provide several needle columns lying next to one another, each with seven to nine print needles placed over one another.
A dot matrix print head with an adjustable needle guide is known from German Published Patent Document DE-OS 26 32 293. In the device disclosed in that document, the print head has print wires placed equidistant in two columns, and the print wire columns are movable in relation to one another in the vertical direction. The print wires of the columns in each case are placed on a support element. One of the support elements is fixedly mounted on the print head carriage, and the other support element is held by a leaf spring at the upper end. The second support element is vertically movable by a cam that can be actuated electromagnetically or manually.
It is further known from German Published Patent Document DE-OS 30 41 877 to make the adjustment element of the dot matrix print head from a lever which is produced from an elastic material and is mounted to swivel around an axis. Such an adjustment element requires, as has been shown, a precise determination of the end positions and a design which results in a flat print head in the area of the print countersupport in order to make a better inspection of the printing process possible. Moreover, an economical production of the part should be assured, also including easy installation. Additionally, as already explained, a special problem is posed by the end positions of the guide orifice, which must be kept very exact because of the desired printing precision for calligraphy.